This thread likely covers the options best starting at this post (it started as a thread on best single class teams to level and morphed into a power-leveling discussion at that post/point):
https://www.dual-boxing.com/threads/...l=1#post425419
IIRC the option to have a main boost up to 4 alts at at time in a dungeon maybe wouldn't be ideal for you as you really want to level a full 5 man team to have a 10man team at cap. In theory you could rotate your team members around so that no single character of your 5man team gets left behind... If I recall correctly most folk said that either a Warrior or Mage was the best to use inside instances and you could try that and report back. To do that 5boxers would need 2 boosters though having a main on a 6th (or 10th account) would likely be easier and would allow for a single main to boost 5 alts (4 at a time & rotating out alts).
The open world tagging approaches would also work for you and shouldn't require swapping. It sounds like there are 2 different rules for open-world tagging:
- Killing by level 60 main(s) of level 48 mobs can even help level 1 characters IF the character(s) to be boosted can tag the mobs...
- Killing by level 60 Pet(s) of any level mob can help after the character(s) to be boosted tag the mobs.
That may give the edge to pet based classes for boosting lower level alts....
EDIT: I recommend you try each of the above that you can accomplish and report back with your thoughts as to which is best (especially for 5boxers moving to become 10boxers).
Edit 2: I will likely start a new thread summarizing these rules so that it isn't buried in thread based on a different topic...
Edit 3: Started the new summary thread and the link is:
https://www.dual-boxing.com/threads/56540-The-Boosting-and-Power-Leveling-summary-thread
Note that this new thread isn't focused on 5boxers moving to become 10boxers and is really for boosting/power leveling in general by mains...